CVE-2021-30657

CRITICALNVD 5.59.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 5.5 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 4 sources updated this weekExploited in the wild
9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 69%CVSS: 5.5Exploit: cisa kev · ssvc active · Metasploit · epss top5pct · epss high · public exploitExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

A logic issue was addressed with improved state management. This issue is fixed in macOS Big Sur 11.3, Security Update 2021-002 Catalina. A malicious application may bypass Gatekeeper checks. Apple is aware of a report that this issue may have been actively exploited..

CVSS v3
5.5
EG Score
9.0(high)
EG Risk
81(Attend)
EG Risk 81/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity90% × 45%
Exploitation100% × 40%
Automatability0% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
69%
EPSS %ILE
99%
KEV
⚠ Exploited

Published

September 8, 2021

Last Modified

October 23, 2025

Advisory Details (3)

Auto-updated Jun 13, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30657
generic🔴 Active Exploitation

About the security content of Security Update 2021-002 Catalina - Apple Support

https://support.apple.com/en-us/HT212326
generic🔴 Active Exploitation

About the security content of macOS Big Sur 11.3 - Apple Support

https://support.apple.com/en-us/HT212325

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 61× in last 7d / 245× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 840 total refreshes for this CVE.

  1. 2026-09-19 06:48 UTCGHSA enrichment
  2. 2026-09-19 02:42 UTCGHSA enrichment
  3. 2026-09-18 22:42 UTCEG score recompute
  4. 2026-09-18 22:42 UTCGHSA enrichment
  5. 2026-09-18 19:23 UTCEPSS rescore
  6. 2026-09-18 19:20 UTCCISA KEV update
  7. 2026-09-18 18:42 UTCGHSA enrichment
  8. 2026-09-18 14:42 UTCGHSA enrichment
  9. 2026-09-18 14:15 UTCCISA KEV update
  10. 2026-09-18 10:41 UTCGHSA enrichment
  11. 2026-09-18 06:41 UTCGHSA enrichment
  12. 2026-09-18 02:41 UTCGHSA enrichment
  13. 2026-09-17 22:41 UTCEG score recompute
  14. 2026-09-17 22:41 UTCGHSA enrichment
  15. 2026-09-17 19:23 UTCEPSS rescore
  16. 2026-09-17 19:23 UTCEPSS rescore
  17. 2026-09-17 18:39 UTCGHSA enrichment
  18. 2026-09-17 14:36 UTCGHSA enrichment
  19. 2026-09-17 10:36 UTCGHSA enrichment
  20. 2026-09-17 06:35 UTCGHSA enrichment
  21. 2026-09-17 02:34 UTCGHSA enrichment
  22. 2026-09-16 22:33 UTCGHSA enrichment
  23. 2026-09-16 18:32 UTCGHSA enrichment
  24. 2026-09-16 14:32 UTCEG score recompute
  25. 2026-09-16 14:32 UTCGHSA enrichment
Show 75 more
  1. 2026-09-16 14:10 UTCCISA KEV update
  2. 2026-09-16 14:05 UTCEPSS rescore
  3. 2026-09-16 10:31 UTCGHSA enrichment
  4. 2026-09-16 06:29 UTCEG score recompute
  5. 2026-09-16 06:29 UTCGHSA enrichment
  6. 2026-09-16 02:29 UTCGHSA enrichment
  7. 2026-09-15 22:29 UTCGHSA enrichment
  8. 2026-09-15 18:29 UTCGHSA enrichment
  9. 2026-09-15 14:29 UTCGHSA enrichment
  10. 2026-09-15 10:29 UTCGHSA enrichment
  11. 2026-09-15 06:29 UTCEG score recompute
  12. 2026-09-15 06:29 UTCGHSA enrichment
  13. 2026-09-15 03:06 UTCEPSS rescore
  14. 2026-09-15 03:06 UTCEPSS rescore
  15. 2026-09-15 02:29 UTCGHSA enrichment
  16. 2026-09-14 22:27 UTCGHSA enrichment
  17. 2026-09-14 19:24 UTCCISA KEV update
  18. 2026-09-14 18:27 UTCGHSA enrichment
  19. 2026-09-14 14:26 UTCGHSA enrichment
  20. 2026-09-14 10:26 UTCGHSA enrichment
  21. 2026-09-14 06:26 UTCGHSA enrichment
  22. 2026-09-14 02:26 UTCGHSA enrichment
  23. 2026-09-13 22:26 UTCGHSA enrichment
  24. 2026-09-13 18:26 UTCEG score recompute
  25. 2026-09-13 18:26 UTCGHSA enrichment
  26. 2026-09-13 16:43 UTCEPSS rescore
  27. 2026-09-13 14:26 UTCGHSA enrichment
  28. 2026-09-13 10:26 UTCGHSA enrichment
  29. 2026-09-13 06:26 UTCGHSA enrichment
  30. 2026-09-13 02:25 UTCGHSA enrichment
  31. 2026-09-12 22:24 UTCGHSA enrichment
  32. 2026-09-12 18:24 UTCEG score recompute
  33. 2026-09-12 18:24 UTCGHSA enrichment
  34. 2026-09-12 14:57 UTCEPSS rescore
  35. 2026-09-12 14:24 UTCGHSA enrichment
  36. 2026-09-12 10:23 UTCGHSA enrichment
  37. 2026-09-12 06:23 UTCGHSA enrichment
  38. 2026-09-12 02:23 UTCGHSA enrichment
  39. 2026-09-11 22:22 UTCGHSA enrichment
  40. 2026-09-11 18:49 UTCCISA KEV update
  41. 2026-09-11 18:21 UTCGHSA enrichment
  42. 2026-09-11 14:20 UTCGHSA enrichment
  43. 2026-09-11 10:20 UTCEG score recompute
  44. 2026-09-11 10:19 UTCGHSA enrichment
  45. 2026-09-11 09:33 UTCEPSS rescore
  46. 2026-09-11 06:16 UTCGHSA enrichment
  47. 2026-09-11 02:16 UTCGHSA enrichment
  48. 2026-09-10 22:16 UTCGHSA enrichment
  49. 2026-09-10 19:28 UTCCISA KEV update
  50. 2026-09-10 18:16 UTCGHSA enrichment
  51. 2026-09-10 14:14 UTCGHSA enrichment
  52. 2026-09-10 10:14 UTCEG score recompute
  53. 2026-09-10 10:14 UTCGHSA enrichment
  54. 2026-09-10 06:14 UTCGHSA enrichment
  55. 2026-09-10 02:14 UTCGHSA enrichment
  56. 2026-09-09 22:14 UTCGHSA enrichment
  57. 2026-09-09 19:08 UTCCISA KEV update
  58. 2026-09-09 18:13 UTCGHSA enrichment
  59. 2026-09-09 14:12 UTCGHSA enrichment
  60. 2026-09-09 10:12 UTCGHSA enrichment
  61. 2026-09-09 06:12 UTCGHSA enrichment
  62. 2026-09-09 02:10 UTCGHSA enrichment
  63. 2026-09-08 22:10 UTCEG score recompute
  64. 2026-09-08 22:10 UTCGHSA enrichment
  65. 2026-09-08 21:56 UTCEPSS rescore
  66. 2026-09-08 18:54 UTCCISA KEV update
  67. 2026-09-08 18:09 UTCGHSA enrichment
  68. 2026-09-08 13:33 UTCGHSA enrichment
  69. 2026-09-08 09:29 UTCGHSA enrichment
  70. 2026-09-08 05:26 UTCGHSA enrichment
  71. 2026-09-08 01:22 UTCGHSA enrichment
  72. 2026-09-07 21:22 UTCGHSA enrichment
  73. 2026-09-07 17:22 UTCEG score recompute
  74. 2026-09-07 17:22 UTCGHSA enrichment
  75. 2026-09-07 15:58 UTCEPSS rescore

Publicly available exploits

(2 references)

Working exploit code is in the public domain (1 Metasploit module) (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCshubham0d/CVE-2021-30657
    First seen Nov 7, 2021

    A sample POC for CVE-2021-30657 affecting MacOS

    Open source ↗
  • Metasploitexploit/osx/browser/osx_gatekeeper_bypass✓ verified
    First seen Mar 25, 2021

    macOS Gatekeeper check bypass

    Open source ↗

Related CVEs(same CWE)

Frequently asked(6)

What is CVE-2021-30657?
CVE-2021-30657 is a critical vulnerability published on September 8, 2021. A logic issue was addressed with improved state management. This issue is fixed in macOS Big Sur 11.3, Security Update 2021-002 Catalina. A malicious application may bypass Gatekeeper checks. Apple is aware of a report that this issue may have been actively exploited..
When was CVE-2021-30657 disclosed?
CVE-2021-30657 was first published in the National Vulnerability Database on September 8, 2021, with the most recent update on October 23, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-30657 actively exploited?
Yes. CISA added CVE-2021-30657 to the Known Exploited Vulnerabilities catalog on November 3, 2021, affecting Apple macOS. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2021-30657?
CVE-2021-30657 has a CVSS v3 base score of 5.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2021-30657?
CVE-2021-30657 affects Apple macOS. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2021-30657?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-30657, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2021-30657

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